T-SQL 向分组数据添加计数器

Question

我正在尝试生成一个查询，该查询显示一个列，该列为每组数据集递增（计数）。结果的总体顺序并不重要，但出现次数必须按日期计数（最旧 = 1）并且应针对每组分组数据进行重置。下面是一个示例表 ProductInteractions。

+---------+------------+----------------+------------+
| User ID | Product ID | Date Purchased | Occurrence |
+---------+------------+----------------+------------+
| user15  | b1290      | 1/1/2012       |          1 |
| user15  | b1290      | 1/15/2013      |          2 |
| user15  | b1290      | 3/15/2019      |          3 |
| user15  | a7983      | 7/22/2017      |          1 |
| user2   | a7983      | 12/3/2015      |          1 |
| user2   | a7983      | 5/6/2016       |          2 |
| user3   | a7983      | 3/24/2017      |          1 |
+---------+------------+----------------+------------+

原始数据：

+---------+------------+-----------+
| User ID | Product ID |   Date    |
+---------+------------+-----------+
| user15  | b1290      | 1/1/2012  |
| user2   | a7983      | 5/6/2016  |
| user15  | b1290      | 3/15/2019 |
| user15  | a7983      | 7/22/2017 |
| user2   | a7983      | 12/3/2015 |
| user15  | b1290      | 1/15/2013 |
| user3   | a7983      | 3/24/2017 |
+---------+------------+-----------+

请注意，在上面的示例中，user15 和产品 b1290 有 3 次交互。重要的是，第一次发生与初始交互日期相关，并且后续交互按增加的日期进行计数。

我相信查询的基本格式将是：

    SELECT [User ID],
           [Product ID],
           [Date Purchased]
           -- Something here utilizing IDENTITY, maybe?
      FROM ProductInteractions
     GROUP BY [User ID],
              [Product ID];

Answer 1

使用ROW_NUMBER()

以下是测试/验证脚本的代码：用您自己的表替换 ProductInteractions

declare @ProductInteractions as table([User ID] varchar(50),[Product ID] varchar(50),[Date] datetime)
insert into @ProductInteractions values
('user15'  , 'b1290'      , '1/1/2012'  ),
('user2'   , 'a7983'      , '5/6/2016'  ),
('user15'  , 'b1290'      , '3/15/2019' ),
('user15'  , 'a7983'      , '7/22/2017' ),
('user2'   , 'a7983'      , '12/3/2015' ),
('user15'  , 'b1290'      , '1/15/2013' ),
('user3'   , 'a7983'      , '3/24/2017' )

select [User ID],[Product ID],[Date],
row_number() over(partition by [User ID],[Product ID] order by [date]) [occurence]
from @ProductInteractions order by [Product ID] desc